ABSTRACT The objective of this study was to evaluate the effectiveness of a litter conditioning compound (LCC) based on 98% phyllosilicates (kaolinite) and 2% cinnamon essential oil to be applied on the litter of broiler houses. Animal performance, prevalence of footpad lesions, and litter quality (water activity, pH, and moisture) were evaluated, in addition to the effect on the incidence of Salmonella spp., evaluated by testing shoe-drag swabs, fecal samples, and organs. Twenty-one broiler houses with similar structure and rearing conditions were distributed in a completely randomized design with three treatments and seven replications each, as follows: T0: control, without the use of LCC; T100: application of 100 grams of LCC per m² of litter per week; T200: application of 200 grams of LCC per m² of litter per week. There was no significant effect of treatments on performance variables; however litter pH was lower when 200g/m2 was used in comparison with the control treatment, a result not verified for moisture and water activity (p>0.05). Our findings demonstrated significant reduction in the percentage of footpad lesions in birds that received the LCC (T0: 63.37%; T100: 41.38% and T200: 27.24%). A reduction in the number of positive flocks for Salmonella spp. Was also observed (with overall positivity rates of 17.86%, 12.14%, and 5% for treatments T0, T100, and T200, respectively). It is concluded that the product reduces the incidence of Salmonella spp. and also significantly reduces the incidence of footpad lesions, two important factors for the poultry industry.

ABSTRACT Brazil is the largest exporter of chicken meat and poultry farming is one of the most important productive segments, despite major losses due to the bacterium Escherichia coli, which is also a zoonotic microorganism. The objetive of this study was to isolate E. coli and to evaluate its transmissibility potential from the field to chicken meat using the Pulsed Field Gel Electrophoresis (PFGE) technique. Environmental samples (poultry litter, soil and water) were collected from broiler farms located in the South of Brazil where the majority of the Brazilian poultry production occurs. In addition, chicken meat (gizzard, heart, drumette and tulip) samples were collected from local supermarkets. As results, 47.36% of the samples were positives for E. coli. Furthermore, 10 pairs of clones of E. coli were found always in the same substrate (two water-water pairs; three soil-soil pairs and five meat-meat pairs) using PFGE. These findings suggest that certain strains of E. coli may have habitat preferences, making the transfer from one substrate type to another more difficult to occur. Moreover, since no clones were found between environmental samples and chicken meat, it is possible to imply a low risk of E. coli transmissibility throughout the chicken meat production chain.

Tinamou (Rhynchotus rufescens) is a native bird of the Brazilian fauna and has great potential to become a domesticated species. From this perspective, the objective of this study was to evaluate the carcass and main parts yield and to assess meat quality of that bird. Two trials, one studying stocking density and the other litter materials, lasting 60 days each, were conducted. The studied traits were evaluated in two birds/replicate/treatment. Performance was evaluated by the least square method. The results showed that bird age at slaughter significantly influenced carcass and breast yields (p<0.05). Mean carcass, breast, thighs+drumstick and wing yields were 86.50±2.78%, 32.84±1.50%, 27.71±1.44%, and 13.21±0.94%, respectively. Shear force, pH, water holding capacity, lightness, redness and yellowness means and standard deviations were 1.92±0.98 kgf.cm-2, 6.07±0.12; 70±0.53%, 48.30±0.96, 1.96±1.01, and 1.61±1.0, respectively. Moisture, ash, crude protein, fat, and cholesterol contents were 72.35±0.16%, 1.12±0.06%, 25.53±0.50%, 0.17±0.01%, and 18.87±2.76 mg/10g, respectively. Results showed carcass and parts yields and the physical-chemical traits of tinamou meat are similar to chicken meat; however, tinamou meat is less acidic and has higher protein level combined with less calories and lower cholesterol levels.

The effects of vitamin E supplementation (300 mg/kg diet) in the diet of broiler chickens for different periods during rearing on the performance and qualitative traits of breast and leg muscles were evaluated. Seven hundred and twenty day-old chicks were distributed into six treatments: basal diet (25 mg vitamin E/kg diet), and diet supplemented with vitamin E from 1 to 15, 1 to 30, 1 to 45, 14 to 45 and 30 to 45 days of age. Vitamin E content, lipid percentage, TBARS (0 and 3 days of storage), color (*L, *a, *b), and pH were evaluated. There were no differences (p>0.05) among treatments in performance, carcass yield, and cut yields. Qualitative parameters (pH and color) presented no differences, although vitamin E positively affected TBARS values at 3 days of storage, mainly in leg muscles. Vitamin E levels in both muscles were higher in the birds supplemented throughout the experiment.

This study evaluated the use of probiotics and prebiotics on the histological and morphological indexes of the intestinal mucosa of broilers at 21 days of age. Thirty-six birds were randomly distributed in a 3 x 3 factorial arrangement, considering 3 probiotics and prebiotics sources in the diet. There were 9 treatments with 4 repetitions. Diet treatments were: 1 - Control (without growth promoters); 2 - Bacillus subtilis-based probiotic (Pro 1); 3 - Probiotic (Pool) based on Lactobacillus acidophilus and casei, Streptococcus lactis and faecium, Bifidobacterium bifidum and Aspergillus oryzae (Pro 2); 4 - Prebiotic based on Phosphorylated Mannanoligosaccharide (MOS) and Organic Acidifier (OA) (Pre 1); 5 - MOS-based prebiotic (Pre 2); 6 - Pro 1 + Pre 1; 7 - Pro 1 + Pre 2; 8 - Pro 2 + Pre 1; 9 - Pro 2 + Pre 2. Higher villus height (VH) (p<0.01) were seen in the duodenum of birds fed diets without prebiotics, whereas birds fed Bacillus subtilis-based probiotic and birds fed prebiotic based on MOS and OA showed higher VH (p<0.01) in jejunum and ileum. Greater crypt depths (CD) (p<0.01) were observed in the duodenum, jejunum and ileum of birds receiving B. subtilis, and in the duodenum and jejunum of birds fed diets without prebiotics. Significant interaction (p<0.01) between the evaluated factors was seen for both, VH and CD, in the three intestinal portions. Greater VH was obtained in duodenum, jejunum and ileum with the use of probiotics and prebiotics and greater CD with the use of probiotics, in relation to the control group. There was no difference in villus density (VD) between birds fed diets without additives or diets containing probiotics and prebiotics. Nevertheless, there was a significant interaction (p<0.05) between the evaluated factors for VD in the duodenum. Concluding, beneficial effects were seen in histological indexes of the intestinal mucosa with the use of probiotics and prebiotics at 21 days of age.

This study evaluated the use of different probiotics, prebiotics and symbiotics on the quality of carcasses and meat of broiler chickens. One hundred and eight day-old Cobb male broilers were used (n=108) in a completely randomized design according to a 3x3 factorial, with 3 probiotics in the diet (no probiotics, probiotics 1, probiotics 2) and 3 prebiotics in the diet (no prebiotics, prebiotics 1, prebiotics 2). There were nine treatments with 4 replicates and 3 birds per replicate. The results showed that the carcass and cut yields, color (L* - lightness, a* - redness, and b* - yellowness), pH, cooking losses, shearing force and sensory analysis were not affected by the use of different growth promoters at 42 days of age. It was concluded that growth promoters supplemented to the diet did not affect the studied quantitative and qualitative parameters of the carcass and breast meat of broiler chickens.

This study evaluated the effect of different probiotics and prebiotics on the performance of broilers. One-day-old male broiler chicks from the Cobb strain (n=1,260) were randomly distributed in a 3 x 3 factorial arrangement, considering 3 probiotics and 3 prebiotics sources. Nine treatments with 4 repetitions and 35 birds per parcel were used. The results showed that there was no influence of treatment on feed intake at the different rearing phases. Better weight gain (p<0.05) was seen when diet was supplemented with the phosphorylated mannanoligosaccharide-based prebiotic (MOS) compared to diets without prebiotics. Feed conversion of birds fed diets with probiotics and prebiotics was better than feed conversion of birds not receiving such additives. Such better results were seen in the initial period (1 to 21 days), but not in the following period (1 to 35 days) or in the total period (1 to 42 days). Better rearing viability was seen when MOS was used together with organic acidifier when compared to the diets without prebiotic. Viability was worst when no prebiotics or probiotics were used. It was concluded that beneficial effects were seen in performance of birds at 21 days when the growth promoters were used, but not at 42 days of age. Nevertheless, there was better growth viability at 42 days of age when growth promoters were added.